Understanding of Materials State and its Degradation using Non-Linear Ultrasound (NLU) Approaches.

摘要

Nonlinear ultrasonic (NLU) harmonic generation to a harmonic wave amplitude input has been simulated in 1D and in 2D using a Mass Spring Lattice Model (MSLM). Previously a Finite Difference Time Domain (FDTD) model was developed in this project. The MSLM model is expected to have improved application for the modeling of the nonlinear behavior of the ultrasonic wave propagation in isotropic and anisotropic materials systems. The 1D MSLM model was developed and the NLU behavior has been simulated and verified using previously reported data. The incorporation of the nonlinear parameters in the 2-D model is currently underway.